1. Field of the Invention
This invention relates to a knife assembly, particularly suitable for a flail apparatus, for mowing or shredding agricultural crop residue and for industrial and commercial mowing or the like, which can be easily replaced in the field without requiring removal of a hanger rod on which it is mounted.
2. Description of Prior Art
Existing flail apparatuses have various rotor designs which incorporate knife elements typically having a hanger bracket with a completely closed or nearly closed curved end which forms an opening through which a hanger rod is mounted. Such conventional curved ends are curved about an arc segment of at least 270.degree., so that the hanger rod must be threaded through the opening in order to retain the knife element in a mounted position on the hanger rod. U.S. Pat. No. 3,092,946 discloses a conventional knife element arrangement.
With the closed or nearly closed curved end arrangement of conventional knife elements, each knife element can be mounted on the hanger rod so that the knife element swings with respect to the hanger rod, or pivots about a longitudinal axis of the hanger rod. To install such conventional knife elements, the hanger rod must be threaded through the opening formed at the curved end of each hanger bracket. Quite often, the hanger rods are relatively long, for example, 15 to 30 feet long. Each hanger rod of such length is often used to mount multiple knife elements.
During operation, hanger brackets of the knife elements can be damaged, for example when the knife element strikes a rock or other relatively hard substance or obstruction. Because the hanger rods are continuous or integral pieces, replacement of a damaged hanger bracket may require removal of the entire hanger rod from its mounted position on the rotor, depending upon the position of the damaged hanger bracket. It is apparent that field maintenance and installation procedures are quite cumbersome and time-consuming, particularly due to the inaccessibility of the rotor as well as ground conditions normally associated with field operations. As the hanger rod is withdrawn from its mounted position on the rotor, the conventional knife elements are dismounted or disassembled with respect to the rotor. Because each individual conventional knife element must be held in position as the relatively long hanger rod is pushed or shoved into its mounted and assembled position, two persons are required to assemble the conventional knife elements in their mounted position, with respect to the rotor.
Thus, a need exists for a detachable knife element which can be easily and readily replaced in the field, by one person, without requiring complete or even partial removal of the hanger rod with respect to the rotor.